| Has
anyone experienced a high speed clicking sound (chatter) with
their electronic fuel pump? I have a univ. 25XP engine with a
fawcett fuel pump. The chatter goes away once the engine is
running a few minutes and the normal slow tick sound is on.
This chatter is only present when i first turn on the engine
key but just started doing it after I changed the raccor
filter.
I think they all do that. The fuel pump works very quickly
until it builds up some pressure then it slows down to the
steady click. (Puff #691 Renate and
Frank)
I recently changed both the filter and the pump, and had a
similar experience. My uneducated guess is you may have a bit
of air in the line. There is a bleeder valve on the engine ...
once I got the air out it worked fine. If it persists, look at
all the connections leading to the pump, including the filter
housing for air leaks... Good luck! (K2/
Stormalong)
We were told by the diesel seminar people that this chatter
was normal as it initially pumped. It's been initially doing
it since day one 9 years ago. No idea why it does it. (AdriennAnn
C34 NAIAD (#1020) LI NY)
wow i got the same thing yesterday, and just asked the yard
about it. they said it was ok, just pumping fuel in. but last
year it was the slow steady clicking, not fast. yard said to
give it a little throttle before starting which i will try(
they just put brake on the throttle cable, maybe that changed
things?) (Ekko1@aol.com)
The high speed chatter on my fuel pump can not be
considered normal operation as some of you have recommended.
In as much as my boat is 9 years old and i just completed a
1600 mile cruise down the ICW this chatter noise was never
present before. The ticking would increase slightly during
starting, but now i have a loud on-going chatter sound. B.
Mueller Karista 1012
Mine did same thing until fuel system vented well. Open
bypass valve to vent to tank. Then reclose. Jeff Salty Dog C34
#1102
Each "click" is one cycle of the fuel pump. The
pump stops running when sufficient pressure has been built up
in the downstream fuel line. It is "normal" when
first starting to have rapid clicks to build up any pressure
that has been lost from the system as the engine was shut
down. During operation, as fuel is injected into the engine,
there will be a steady slow click for fuel makeup -- the
"speed" of the clicks depends on the current fuel
consumption of the engine. However, if the fuel pump continues
to click rapidly then I would suspect one of three conditions:
1. you have a leak in the fuel system -- some leaks can be
internal so may not be seen outside the engine
2. air trapped somewhere in the system
3. your pump diaphram has a tear.
Since you just changed your Racor filter, I would suspect
that it isn't installed correctly or you let too much air into
the system that hasn't been evacuated. If the fuel pump can
suck in air at the filter, it might continue to run because it
is slightly air bound, but not air-bound enough to shut down
the engine. I'd take the new filter off and reinstall it, and
then go through the system bleed procedure. Pete
I addition to the already mentioned possible causes of the
fuel pump chatter, please consider that the fuel bypass valve
may be partially open allowing fuel to pump back to the tank.
This would reduce pressure and cause the pump to run faster
than usual. Paul Law #912 Avalon
Comment from C34 Tech Notes Editor Ron Hill
As you can see from the replies that you've seen to date,
there can be a number of causes for the fuel pump pulsing very
rapidly. Normal pulsing should be about one pulse every two
seconds without the engine running. As one of your replies
mentioned, an open bleed valve could be the cause. As I've
written in a number of Mainsheet articles, you could also have
a clogged fuel screen pick up tube in
the fuel tank and the pump is trying to suck fuel through a
clogged strainer. If this anomaly just started after you
changed the Racor filter, it sounds as though the Racor filter
may not be seated properly and you are getting an air leak; or
you did not completely get all of the air out of the new Racor
filter. I'd recommend you reseat your Racor filter to ensure
that the flat gasket at the top and the O ring at the bottom
are completely seated. Then I would repurge the system using
the bleed valve until you can completely close the bleed valve
without the engine running and hear the rhythmic tick every
two seconds. Ron, Apache #788
Important: The opinions expressed
here are those of the individual contributors to this page,
and not those of the Catalina 34 National Association or
Catalina Yachts, Inc. Additionally, this material has not been
reviewed by Catalina Yachts, Inc. for technical accuracy. This
page's maintainer cannot guarantee the accuracy of this
information or the desirability of suggested modifications or
upgrades. Please obtain assistance from a competent marine
mechanic or boatyard prior to making any significant
modifications to your vessel. |
